[C++ bindings] Add move-assign operator, require rvalue for move

[rust-lightning] / c-bindings-gen / src / blocks.rs

diff --git a/c-bindings-gen/src/blocks.rs b/c-bindings-gen/src/blocks.rs
index 606131a679d011df6a5bc92580802aa53959ce8a..107c72b3db4b97a852cd0c1a84c8b17ed8d92d7d 100644 (file)
--- a/c-bindings-gen/src/blocks.rs
+++ b/c-bindings-gen/src/blocks.rs
@@ -16,12 +16,15 @@ pub fn write_cpp_wrapper(cpp_header_file: &mut File, ty: &str, has_destructor: b
        writeln!(cpp_header_file, "\tLDK{} self;", ty).unwrap();
        writeln!(cpp_header_file, "public:").unwrap();
        writeln!(cpp_header_file, "\t{}(const {}&) = delete;", ty, ty).unwrap();
+       writeln!(cpp_header_file, "\t{}({}&& o) : self(o.self) {{ memset(&o, 0, sizeof({})); }}", ty, ty, ty).unwrap();
+       writeln!(cpp_header_file, "\t{}(LDK{}&& m_self) : self(m_self) {{ memset(&m_self, 0, sizeof(LDK{})); }}", ty, ty, ty).unwrap();
+       writeln!(cpp_header_file, "\toperator LDK{}() && {{ LDK{} res = self; memset(&self, 0, sizeof(LDK{})); return res; }}", ty, ty, ty).unwrap();
        if has_destructor {
                writeln!(cpp_header_file, "\t~{}() {{ {}_free(self); }}", ty, ty).unwrap();
+               writeln!(cpp_header_file, "\t{}& operator=({}&& o) {{ {}_free(self); self = o.self; memset(&o, 0, sizeof({})); return *this; }}", ty, ty, ty, ty).unwrap();
+       } else {
+               writeln!(cpp_header_file, "\t{}& operator=({}&& o) {{ self = o.self; memset(&o, 0, sizeof({})); return *this; }}", ty, ty, ty).unwrap();
        }
-       writeln!(cpp_header_file, "\t{}({}&& o) : self(o.self) {{ memset(&o, 0, sizeof({})); }}", ty, ty, ty).unwrap();
-       writeln!(cpp_header_file, "\t{}(LDK{}&& m_self) : self(m_self) {{ memset(&m_self, 0, sizeof(LDK{})); }}", ty, ty, ty).unwrap();
-       writeln!(cpp_header_file, "\toperator LDK{}() {{ LDK{} res = self; memset(&self, 0, sizeof(LDK{})); return res; }}", ty, ty, ty).unwrap();
        writeln!(cpp_header_file, "\tLDK{}* operator &() {{ return &self; }}", ty).unwrap();
        writeln!(cpp_header_file, "\tLDK{}* operator ->() {{ return &self; }}", ty).unwrap();
        writeln!(cpp_header_file, "\tconst LDK{}* operator &() const {{ return &self; }}", ty).unwrap();
@@ -274,34 +277,12 @@ pub fn write_method_call_params<W: std::io::Write>(w: &mut W, sig: &syn::Signatu
                syn::ReturnType::Type(_, rtype) => {
                        write!(w, ";\n\t{}", extra_indent).unwrap();
 
+                       let self_segs_iter = first_seg_self(&*rtype);
                        if to_c && first_seg_self(&*rtype).is_some() {
                                // Assume rather blindly that we're returning an associated trait from a C fn call to a Rust trait object.
                                write!(w, "ret").unwrap();
-                       } else if !to_c && first_seg_self(&*rtype).is_some() {
-                               if let Some(mut remaining_path) = first_seg_self(&*rtype) {
-                                       if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
-                                               // Build a fake path with only associated_seg and resolve it:
-                                               let mut segments = syn::punctuated::Punctuated::new();
-                                               segments.push(syn::PathSegment {
-                                                       ident: associated_seg.clone(), arguments: syn::PathArguments::None });
-                                               let (_, real_path) = generics.unwrap().maybe_resolve_path(&syn::Path {
-                                                       leading_colon: None, segments }).unwrap();
-
-                                               assert_eq!(real_path.segments.len(), 1);
-                                               let real_ident = &real_path.segments.iter().next().unwrap().ident;
-                                               if let Some(t) = types.crate_types.traits.get(&types.maybe_resolve_ident(&real_ident).unwrap()) {
-                                                       // We're returning an associated trait from a Rust fn call to a C trait
-                                                       // object.
-                                                       writeln!(w, "let mut rust_obj = {} {{ inner: Box::into_raw(Box::new(ret)), is_owned: true }};", this_type).unwrap();
-                                                       writeln!(w, "\t{}let mut ret = {}_as_{}(&rust_obj);", extra_indent, this_type, t.ident).unwrap();
-                                                       writeln!(w, "\t{}// We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn", extra_indent).unwrap();
-                                                       writeln!(w, "\t{}rust_obj.inner = std::ptr::null_mut();", extra_indent).unwrap();
-                                                       writeln!(w, "\t{}ret.free = Some({}_free_void);", extra_indent, this_type).unwrap();
-                                                       writeln!(w, "\t{}ret", extra_indent).unwrap();
-                                                       return;
-                                               }
-                                       }
-                               }
+                       } else if !to_c && self_segs_iter.is_some() && self_segs_iter.unwrap().next().is_none() {
+                               // If we're returning "Self" (and not "Self::X"), just do it manually
                                write!(w, "{} {{ inner: Box::into_raw(Box::new(ret)), is_owned: true }}", this_type).unwrap();
                        } else if to_c {
                                let new_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("ret", Span::call_site()), rtype, generics);